Crack in bellhousing

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Princess Valiant

A.K.A. Rainy Day Auto
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Is this something to really be worried about?

Do you guys think I can mig weld it to seal it up and go ?

It's a cast iron bell

20190209_213236.jpg
 
Well.......you're gonna need to find the end of that crack and drill a hole there to stop it. Otherwise, it will continue to crack. From there, you can decide on how to proceed to weld. Honestly, IMO, I think if you try to MIG that, you will create new cracks. Do you have a torch that you can pre-heat the area with? If so, you can pre-heat, weld, pre-heat, weld until you get it done. Even then, you risk cracks, because MIG is so hot so quick. I think I would try drilling the hole and then brazing it up. Is that for a small block NP 435? I have a good bell housing if you decide to go that route.
 
Drill the end of the crack and pin it or TIG it. Id run a welded up bell. How much stress is on it with all the bolts?
 
Well.......you're gonna need to find the end of that crack and drill a hole there to stop it. Otherwise, it will continue to crack. From there, you can decide on how to proceed to weld. Honestly, IMO, I think if you try to MIG that, you will create new cracks. Do you have a torch that you can pre-heat the area with? If so, you can pre-heat, weld, pre-heat, weld until you get it done. Even then, you risk cracks, because MIG is so hot so quick. I think I would try drilling the hole and then brazing it up. Is that for a small block NP 435? I have a good bell housing if you decide to go that route.
This is actually a slant six bell for an NP 435.

I doubt I would find a replacement, the small block ones seem to be more common.

This and the fact that the six turned out to be frozen make a small block look appealing.

20190209_213258.jpg
 
This is actually a slant six bell for an NP 435.

I doubt I would find a replacement, the small block ones seem to be more common.

This and the fact that the six turned out to be frozen make a small block look appealing.

View attachment 1715287405

Hun, if I am looking at that right, I believe it has bosses for a small block, too. I think it will fit both. It appears one of the bosses isn't drilled, although that would be an easy fix. Get a small block bell housing and compare and see if I'm not right.
 
As a certified welder “IF” you want to fix it
1) remove the bell housing completely and clean it spotless.
2) you need to pre- heat the cast to 400 degrees. A kitchen oven is perfect.... hense the clean it spotless.
3) drill the end of the crack with at least a 1/8” drill bit slow and steady so you don’t break the drill off in the hole. Drill all the way thru. I like to step it up to 1/4”
4) Go to a real welding store like Airgas or basically a welding supply store that only sells welding and cutting equipment. Places that sell Forney welding supplies typically hardware stores are not a good choice and the people have no experience in this matter but “I know a guy” stories. Forney stuff could be sitting on a shelf for years collecting dampness. There products are marginal at best and again old. You want new fresh welding rods. Typically referred to as “Ni-rod” there are different grades of cast welding rods. Based on make up of metal. Tell the counter guy you are welding older automotive cast steel. They will put you in the right direction.
5) grind the crack in a “v” with about 1/8” left at the base. The top of the “v” should be about 3/8” wide. Don’t grind thru the base metal.
6) put your “spotless” cleaned bell housing in the kitchen cold oven. Turn on the oven to 400 degrees and let bake for approx 1 hr minimum. (Wife will question or debate this process) have a old blanket ready.
7) leave oven running and after 1 hr remove the part. Wrap immediately in blanket to keep warm.
8) following recommendation by weld rod manufacture weld up the cracks using AWS D1.1 procedures. (I know a bit much but I am a professional welder)
9) after done welding - keeping blanket as much on the part as possible to keep as close to 400 degrees as possible. Bring back to oven and remove blanket and put part back in. Run oven for 1 more hour at 400 to stabilize part heat zone.
10) shut off oven and do not open the door and then allow to slowly cool - I typically allow over night.

If you do everything correctly it will weld properly. If you don’t- it will re crack.
This is why most choose to buy a different part. A lot of work for possibly little reward. My clients and customers typically think welding cast is a walk in the park but it is far from that.
Joe
 
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As a certified welder “IF” you want to fix it
1) remove the bell housing completely and clean it spotless.
2) you need to pre- heat the cast to 400 degrees. A kitchen oven is perfect.... hense the clean it spotless.
3) drill the end of the crack with at least a 1/8” drill bit slow and steady so you don’t break the drill off in the hole. Drill all the way thru. I like to step it up to 1/4”
4) Go to a real welding store like Airgas or basically a welding supply store that only sells welding and cutting equipment. Places that sell Forney welding supplies typically hardware stores are not a good choice and the people have no experience in this matter but “I know a guy” stories. Forney stuff could be sitting on a shelf for years collecting dampness. There products are marginal at best and again old. You want new fresh welding rods. Typically referred to as “Ni-rod” there are different grades of cast welding rods. Based on make up of metal. Tell the counter guy you are welding older automotive cast steel. They will put you in the right direction.
5) grind the crack in a “v” with about 1/8” left at the base. The top of the “v” should be about 3/8” wide. Don’t grind thru the base metal.
6) put your “spotless” cleaned bell housing in the kitchen cold oven. Turn on the oven to 400 degrees and let bake for approx 1 hr minimum. (Wife will question or debate this process) have a old blanket ready.
7) leave oven running and after 1 hr remove the part. Wrap immediately in blanket to keep warm.
8) following recommendation by weld rod manufacture weld up the cracks using AWS D1.1 procedures. (I know a bit much but I am a professional welder)
9) after done welding - keeping blanket as much on the part as possible to keep as close to 400 degrees as possible. Bring back to oven and remove blanket and put part back in. Run oven for 1 more hour at 400 to stabilize part heat zone.
10) shut off oven and do not open the door and then allow to slowly cool - I typically allow over night.

If you do everything correctly it will weld properly. If you don’t- it will re crack.
This is why most choose to buy a different part. A lot of work for possibly little reward. My clients and customers typically think welding cast is a walk in the park but it is far from that.
Joe
Awesome advice!
Cudos to you for explaining this process so well.
As a journeyman welder myself, i have used this exact procedure with excellent results.
I have repaired all sorts of castings such as bell housings, exhaust manifolds, cast iron transmission pans, etc. with Ni Rod and it works great.
I have used brass rods and have done it with a torch as well.
The Ni Rod is my preference.
If you don't have Ni Rod, you could use a 308 stainless steel rod in a pinch.
I usually would weld only 1/2'' at a time and use an air peaner to pean the weld.
In the field, i would heat the part to a dull cherry red with a rosebud tip 4'' or so around the crack and weld it up.
After welding, I then would put the part in a wooden box and wrap the part in insulation and leave over night to cool slowly.
Do not use the mig, unless you have no other alternative, and if you did, use lots of preheat and hope for the best.
 
what do you supposed the cause of the crack was? Crack is at about 11:00 facing the bell? Is it at a bolt boss? How about a structural strap bolted over the crack? Just thinking no AWS D1.1 capable garage fixes here.....
 
Dartnut. Keep up the career. Excellent long term financial benifit you will always have work.
After alomost 30years take my advice-
Wear ear protection-you do not want the ringing in my ears 24/7
Wear eye protection always!
Also wear breathing equipment if you can.
These fumes cause cancer. It cannot be totally avoided but every bit helps. Great career choice. It is a needed field with many many options with good training.
Also gloves are huge. A lot of tv shows have guys welding with out gloves- bad choice. I wear Tillman truck driver gloves all the time minimum just for the UV protection. You only have one skin.
Sorry to side track thread. Just happy to see another fellow rod burner. Lol!
 
.................Or clean it...........preheat it.........and braze it.............
 
I've used a tig on cast iron with stainless rods (316L) and it worked well. That part is still in service (wrench, used daily by owner).

How does this typically fare to the above process with the oven and Nickel rods? Did I just get lucky?
 
what do you supposed the cause of the crack was? Crack is at about 11:00 facing the bell? Is it at a bolt boss? How about a structural strap bolted over the crack? Just thinking no AWS D1.1 capable garage fixes here.....
More than likely the housing was bolted together to the block and something was in between the two or did the clutch come apart. It is a very strange crack after all these years. I’d put some technical data out there but it might overwhelm Pishta. Lol! :)
 
Also Gang-

Anyone can “weld up the crack.” “Fill the gap” “glue it.” Etc. You have to decide what level you want it repaired at. If it is for “looks only” then snot it up and grind it down. If you want it for heavy work then replace it. Or pick your poison any where in between and go for it. Worst case is you mess it up and have to buy a good used one. ;)
 
I have a local friend who will be 81 this year. He's been a certified welder since he was 20. He could fix that, permanently and forever. Seen him do similar before. It's time consuming to do it right. Vee it out, pre-heat, weld some, let cool peen and repeat. He's a master still working 12-14 hours a day at one of the local aggregate quarries right down the road from here. He's 6'6" and about 320 and even at 81, I wouldn't jump on him with two of me. He used to race fueler Hemi car back in the day. He's quite the character.
 
Joe,I'm a retired QA/welding engineer, and I must say this is the best written article on how to repair cast iron I've sen in a long time.
 
Joe,I'm a retired QA/welding engineer, and I must say this is the best written article on how to repair cast iron I've sen in a long time.


Wow! Thank you retroron.
I appreciate the compliment. I wish the “powers at be” would copy and paste that for future reference for others out side this thread.
 
It all gets down to
Do you value your feet.
Ever seen a bell housing explosion.
Why chance it?
 
Grab a piece of steel,And grind it.
Then grind on bellhousing.
If its cast, the sparks wont be as white/bright as the previously ground steel.
Could be cast steel. Then you could stop drill and weld away.
 
Joe,I'm a retired QA/welding engineer, and I must say this is the best written article on how to repair cast iron I've sen in a long time.
Agreed!
I believe all of the credit goes to Syleng 1 for the good explanation, i only added my two bits.
 
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you can weld it if it makes you feel better , if it was mine I would bore a hole at the end of the crack and put it on straight and square and run it .
 
Dartnut. Keep up the career. Excellent long term financial benifit you will always have work.
After alomost 30years take my advice-
Wear ear protection-you do not want the ringing in my ears 24/7
Wear eye protection always!
Also wear breathing equipment if you can.
These fumes cause cancer. It cannot be totally avoided but every bit helps. Great career choice. It is a needed field with many many options with good training.
Also gloves are huge. A lot of tv shows have guys welding with out gloves- bad choice. I wear Tillman truck driver gloves all the time minimum just for the UV protection. You only have one skin.
Sorry to side track thread. Just happy to see another fellow rod burner. Lol!
Agreed 100%!
I sure wish that i was able to be active in the trade still.
However, after two knee surgeries, back problems, and now arthritis, i was forced to find another occupation.
The over 20 years i spent in the trade were good to me, and i loved it.
Also, i was always very big on wearing PPE, a lot of it before it became mandatory.
Nice to see another welder on here as well!

Back to the thread discussion, that is an unusual place for the bell housing to crack.
Unless it was removed some time ago and dropped, had loose bolts, or something got between the mating surface between the block and the bell housing, i would bet that it is a casting flaw.
I've actually seen some castings that were so poorly done that they had ''pockets'' of carbon or bad porosity in them.
The crack appears to me to have been there some time because of the rust in the crack.
Finally, if repaired properly, the part would be as good as new or even better.............
 
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